Reading the SEC document too closely will give you a headache, but here's how it worked, as we currently understand it:

Google created Maple Technologies as a wholly owned subsidiary.

Maple Technologies was given a controlling share of Google by Google.

The newly formed Alphabet "acquired" Maple Technologies.

Now Alphabet owns Google.

Maple Technologies, no longer necessary, merges back into Google — the subsidiary — and is discarded.

This kind of shuffle is pretty common in corporate America. If you're ever watching a spy TV show and they mention "shell companies," this is kind of what they're talking about.

But why "Maple Technologies"? We don't know. Maybe Larry and Sergey like their syrup ...

Here's how the company described it in various SEC filings:

On October 2, 2015, the registrant implemented a holding company reorganization (the "Alphabet Merger") pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated as of October 2, 2015, among the registrant, Alphabet Inc., a Delaware corporation ("Alphabet") and Maple Technologies Inc., a Delaware corporation ("Merger Sub"), which resulted in Alphabet owning all of the outstanding capital stock of the registrant. Pursuant to the Alphabet Merger, Merger Sub, a direct, wholly owned subsidiary of Alphabet and an indirect, wholly owned subsidiary of the registrant, merged with and into the registrant, with the registrant surviving as a direct, wholly owned subsidiary of Alphabet.